The present invention relates generally to vibratory feeders of the type having an elongated track and operable to feed parts forwardly along the track by longitudinal oscillation or vibration of the track. The present invention relates more particularly to a new and improved vibratory feeder of the type described having a configuration of component parts providing superior performance and greater design flexibility.
Examples of vibratory feeders of the type described are disclosed in U.S. Pat. No. 3,786,912, dated Jan. 22, 1974 and entitled "Linear Vibratory Feeder" and U.S. Pat. No. 4,260,052, dated Apr. 7, 1981 and entitled "Vibratory Feeder Leaf Spring Arrangement". In such vibratory feeders, the parts are fed forwardly along an elongated linear track by longitudinal vibratory motion of the track generally parallel to but inclined upwardly from the longitudinal axis of linear feed. Thus, the vibratory motion has a primary component parallel to the axis of feed and a secondary component normal to the axis of feed. As the vibrating track moves in a forward direction, it carries each part forwardly a small step while propelling the part upwardly normal to the axis of feed. As the vibrating track moves in the opposite direction, each part floats partly or fully on or above the track support surface. That cycle is repeated at a high frequency to feed the parts in small steps forwardly along the track.
Such vibratory feeders typically are used to transport parts in succession from a bowl feeder to an escapement, deadnest or other part receiver. Storage and orientation of the parts is normally provided by the bowl feeder. In some applications, it is essential that there be smooth and consistent track motion normal to the axis of feed along the full length of the track to maintain part orientation and to ensure that the parts are fed evenly along the track. Smooth and consistent track motion normal to the axis of feed is also necessary if the track has an overlying or other retaining structure for retaining the parts on the track. Otherwise, excessive track vibration normal to the axis of feed can cause the parts to engage the retaining structure and to be fed backwardly by the retaining structure during the reverse motion of the track.
When vibratory feeders of the type described are operated to produce the desired vibratory motion of the track, additional undesirable track vibrations are usually produced. For example, an undesirable track vibration is produced by the oscillating force couple which produces the desired vibratory motion. This undesirable vibration is particularly problematic because it has a component normal to the axis of feed which varies along the length of the track. Specifically, the normal component increases along the track in opposite directions from approximately the midpoint of the track. Where the intended and undesirable components normal to the direction of feed are additive, the resultant track motion normal to the direction of feed can cause the parts to bounce excessively. Where the intended and undesirable normal components are subtractive, the resultant track motion normal to the direction of feed can be inadequate to properly feed the parts or in extreme situations can feed the parts backwardly.
It is often desirable to employ a track substantially longer than the track platform used to support and vibrate the track. However, lengthening the track magnifies the undesirable component of vibration normal to the direction of feed. The magnified vibration in combination with the greater track flexure at the outer ends of the track significantly compounds the problem. Track motion normal to the axis of feed can be excessive at one end of the track and insufficient or even out-of-phase at the other end of the track. As a consequence, the parts may bounce excessively at one end of the track, stop at an intermediate point of zero or reduced vibratory motion and be fed backwardly at the opposite end of the track.
A principal aim of the present invention is to provide a new and improved vibratory feeder of the type described which provides generally smooth and consistent track motion normal to the axis of feed along the full length of the track.
Another aim of the present invention is to provide a new and improved vibratory feeder of the type described which provides a higher feed rate by providing increased track motion in the direction of feed. In accordance with the present invention, a relatively low angle of inclination of intended vibratory motion is provided which increases the intended track motion in the direction of feed and reduces the intended track motion normal to the direction of feed.
Another aim of the present invention is to provide a new and improved vibratory feeder of the type described having an oscillating two-mass system which is supported to minimize the transmission of vibrations to and from the two-mass system, to minimize the resistance to oscillation and to minimize the absorption of energy from the oscillating system.
A further aim of the present invention is to provide a new and improved vibratory feeder of the type described useful with tracks of different lengths and weights and with tracks mounted at different longitudinal positions on the vibratory feeder.
Another aim of the present invention is to provide a new and improved vibratory feeder of the type described having a low profile and an oscillating two-mass system with a short moment arm between the centers of gravity of the two oscillating masses.
Another aim of the present invention is to provide a new and improved vibratory feeder of the type described which is economical to manufacture, easy to assemble and disassemble and which permits ready modification and adjustment. According to the present invention, the vibratory feeder has a new and improved configuration of component parts which provides greater flexibility in tuning the feeder for each application.
Other objects will be in part obvious and in part pointed out more in detail hereinafter.
A better understanding of the invention will be obtained from the following detailed description and the accompanying drawings of an illustrative application of the invention.